Managing HP Serviceguard for Linux Ninth Edition, April 2009

ensures that for each capacity configured for a node, the combined weight of packages
currently running on that node does not exceed that capacity.
For example, if you define a CAPACITY_NAME and weight_name processor, and a
CAPACITY_NAME and weight_name memory, and a node has a processor capacity
of 10 and a memory capacity of 1000, Serviceguard ensures that the combined
processor weight of packages running on the node at any one time does not exceed
10, and that the combined memory weight does not exceed 1000. But Serviceguard has
no knowledge of the real-world meanings of the names processor and memory; there
is no mapping to actual processor and memory usage and you would get exactly the
same results if you used the names apples and oranges, for example.
Suppose you have the following configuration:
• A two node cluster running four packages. These packages contend for resource
we'll simply call A and B.
• node1 has a capacity of 80 for A and capacity of 50 for B.
• node2 has a capacity of 60 for A and capacity of 70 for B.
• pkg1 uses 60 of the A capacity and 15 of the B capacity.
• pkg2 uses 40 of the A capacity and 15 of the B capacity.
• pkg3 uses insignificant amount (zero) of the A capacity and 35 of the B capacity.
• pkg4 uses 20 of the A capacity and 40 of the B capacity.
pkg1 and pkg2 together require 100 of the A capacity and 30 of the B capacity. This
means pkg1 and pkg2 cannot run together on either of the nodes. While both nodes
have sufficient B capacity to run both packages at the same time, they do not have
sufficient A capacity.
pkg3 and pkg4 together require 20 of the A capacity and 75 of the B capacity. This
means pkg3 and pkg4 cannot run together on either of the nodes. While both nodes
have sufficient A capacity to run both packages at the same time, they do not have
sufficient B capacity.
Example 2
To define these capacities, and set limits for individual nodes, make entries such as the
following in the cluster configuration file:
CLUSTER_NAME cluster_23
...
NODE_NAME node1
...
CAPACITY_NAME A
CAPACITY_VALUE 80
CAPACITY_NAME B
132 Planning and Documenting an HA Cluster